Washington (CNN) - Newt Gingrich will leave the Republican presidential campaign with a mixed legacy and a campaign deep in debt.

The former speaker was left for political dead last year after his top campaign advisers quit over a disagreement on the direction of the campaign and its financial structure. But he came roaring back in late 2011 - due in part to a Republican electorate that was not sold on Mitt Romney's candidacy. It is the past few months, though, for which he may be most remembered - for staying in the race for too long, rather than for the big ideas he espoused on the campaign trail.